Meta-analysis of narrow-band imaging versus conventional colonoscopy for adenoma detection

Background At colonoscopy, missed adenomas have been well documented at approximately 22%. The challenge is in reducing this miss rate. Narrow-band imaging (NBI) has been extensively evaluated in prospective, randomized, controlled studies for polyp detection. Sample-size calculations show us that these studies may be underpowered, and hence a meta-analysis is required. Objective Our aim was to determine whether use of NBI enhances the detection of adenomas. Design Meta-analyses were conducted of 7 studies using NBI for adenoma detection rate. MEDLINE, Embase, PubMed, and Cochrane databases were searched by using a combination of the following terms: “colonoscopy,” “NBI,” and “electronic chromoendoscopy.” Patients There was a total of 2936 patients in the NBI studies. Interventions Prospective, randomized trials of NBI versus standard white-light colonoscopy (WLC) were conducted. We excluded spray chromoendoscopy studies and studies of inflammatory bowel disease and polyposis syndromes. Main Outcome Measurements Adenoma and polyp detection rates and the number of polyps and adenomas detected per person. Results There was no statistically significant difference in the overall adenoma detection rate with the use of NBI or WLC (36% vs 34%; P = .413 [relative risk 1.06; 95% CI, 0.97-1.16]), and there was no statistically significant difference in polyp detection rate by using NBI or WLC (37% vs 35%; P = .289 [relative risk 1.22; 95% CI, 0.85-1.76]). When the number of adenomas and polyps per patient was analyzed, no significant difference was found between NBI and WLC (0.645 vs 0.59; P = .105 and 0.373 vs 0.348; P = .139 [weighted mean difference 0.19; 95% CI, ∞0.06 to 0.44], respectively). Limitation Variability in NBI studies can reduce the accuracy of this analysis. Conclusions NBI did not increase adenoma or polyp detection rates.